package mx

import (
	//"github.com/hajimehoshi/ebiten/v2"
	"math"
)

var (
	ZV = V2(0)
)

type Vector struct {
	X, Y Float

}
type Vectors []Vector

func (v Vector) XY() (Float, Float) {
	return v.X, v.Y
}

func V(x, y Float) Vector {
	return Vector{x, y}
}

func V2(v Float) Vector {
	return Vector{v, v}
}

func VX(x Float) Vector {
	return Vector{x, 0}
}

func VY(y Float) Vector {
	return Vector{0, y}
}

func (v Vector) Div(o Vector) Vector {
	return V(
		v.X / o.X,
		v.Y / o.Y,
	)
}

func (v Vector) Mul(o Vector) Vector {
	return V(
		v.X * o.X,
		v.Y * o.Y,
	)
}

func (v Vector) Eq(o Vector) bool {
	return v.X == o.X && v.Y == o.Y
}

// Returns the vector with the matrix applied
func (v Vector) Apply(m Matrice) Vector {
	x, y := m.Apply(v.X, v.Y)
	return Vector{x, y}
}

// Adds the vector to other one returning the result.
func (v Vector) Add(a Vector) Vector {
	v.X += a.X
	v.Y += a.Y
	
	return v
}

// Returns the subtraction of all the vectors from the current one.
func (v Vector) Sub(s Vector) Vector {
	v.X -= s.X
	v.Y -= s.Y
	
	return v
}

// Returns the negative version of the vector.
func (v Vector) Neg() Vector {
	return Vector{
		-v.X,
		-v.Y,
	}
}

// Returns the vector rotated by "a" angle in radians.
func (v Vector) Rot(a Float) Vector {
	m := Matrice{}
	m.Rotate(a)
	return v.Apply(m)
}

// Returns the normalized vector.
func (v Vector) Norm() Vector {
	l := math.Sqrt(v.X*v.X + v.Y*v.Y)
	return V(v.X / l, v.Y / l)
}

func (pts Vectors) PointsContainedIn(
	c PointContainer,
) Vectors {
	ret := make(Vectors, 0, len(pts))
	
	for _, pt := range pts {
		if c.ContainsPoint(pt) {
			ret = append(ret, pt)
		}
	}
	
	return ret
}